Understanding the whole forest — above and below the ground — is critical to understanding forest and watershed health. Much of the early work on the importance and extent of the forest below the ground was done at Oregon State University. But the lessons seem to be ignored in the current debates over the fate of federal forests in the Pacific Northwest. The consequences of ignoring the complexity of relationships between the above and below ground forest was demonstrated in an unexpected way on the Siskiyou National Forest during the 1997 New Years Day Storm (photos below).
In this short video, University of British Columbia researcher, Suzanne Simard, explains the amazing below ground forest and how trees communicate and cooperate in creating a healthy resilient forest.
This is not new information but Dr. Simard, who received her PhD at Oregon State University, continues to advance and expand on the research. In the abstract for “Response Diversity of Ectomycorrhizas in Forest Succession Following Disturbance,” Dr. Simard writes that :
… severe disturbances, such as clearcutting followed by site preparation that removes living trees, root systems, or forest floor, can reduce [ectomycorrhizal fungal species] diversity on regenerating seedlings, often corresponding with reduced survival, growth rates, and foliar nutrients.
This is exactly what was happening in the 1970s, where “cut, slash and burn” logging practices sometimes converted high elevation forests into permanent clearcuts on the Siskiyou National Forest. The site pictured below is east of the Oregon Caves National Monument in the Left Fork Sucker Creek Watershed. It was clearcut in the 1970s and planted numerous times. The photo, taken in 1997, shows nothing much grew back and one of the unacknowledged consequences of the deforestation. The result of deforesting deep granitic soils and road construction, combined with the 1997 New Years Day Storm (a rain-on-snow event), are seen on the slope and road below.
The next photo shows were the debris flow—beginning at the road cut failure on the deforested slope above—resulted in a plugged culvert on FS road 4612-080, above the Left Fork of Sucker Creek, a beautiful steelhead nursery.
The culverts in the road system were supposed to have been upgraded the year before to handle a 100 year storm event. The road system upgrade was part of the controversial China-Left timber sale, but the timber sale planners didn’t take into consideration the potential for slope/road cut failure from the past management practices in the watershed above. The next photo shows what happened in between the permanent clearcut and the recently upgraded road system and that not only are forest ecosystems complex but so-called forest management (roads and logging) often results in a cascade of impacts that never seem to be anticipated.
There are consequences of seeing trees only as a commodity—to be grown like a crop—instead of one interdependent part of a complex ecosystem that’s watershed to our streams and rivers. See also:
- Suzanne Simard and Mary Austin, “The role of mycorrhizas in forest soil stability with climate change.”
- D. A. PERRY, J. G. BORCHERS, S. L. BORCHERS, M. P. AMARANTHUS, Species Migrations and Ecosystem Stability During Climate Change: The Belowground Connection –